Deterioration mechanism of sulfoaluminate concrete at high temperature

Abstract

In order to explore the deterioration law and mechanism of sulfoaluminate concrete under high temperature environment, this paper studied the deterioration law of sulfoaluminate concrete by observing the crack changes of sulfoaluminate concrete samples under different water/cement ratio, different ages and different temperatures after experiencing different high temperatures, and measuring the residual mass ratio, infrared temperature rise, ultrasonic pulse speed and compressive strength. The results show that the loss of strength and mass is the fastest when the temperature of sulfoaluminate concrete is 200 °C, and the loss of strength and mass becomes slower and slower with the increase in temperature. The main reasons for the deterioration of sulfoaluminate concrete are the destruction of microstructure by ettringite and Ca(OH)2 by dehydration at high temperature. The higher the initial strength of sulfoaluminate concrete, the greater the strength loss after high temperature, but the higher the residual strength.